000 AXPZ20 KNHC 210304 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI SEP 21 2012 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...SPECIAL FEATURES... SURFACE LOW PRES 1007 MB EMBEDDED IN MONSOON TROUGH AT 14N103W. IT IS EXPECTED TO DRIFT W-NW AND INTENSIFY REACHING 14N105W EARLY FRI AND 15N108W EARLY SAT. TROPICAL CYCLONE FORMATION EXPECTED WITHIN NEXT 24-36 HRS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTEND FROM 09N84W TO 1007 MB LOW PRES 14N103W TO 11N125W THEN ITCZ TO 09N133W TO BEYOND 07N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM N SEMICIRCLE OF LOW PRES CENTER AT 14N103W. SCATTERED MODERATE CONVECTION WITHIN 120 NM S OF AXIS FROM 128W TO 138W. ...DISCUSSION... BROAD ANTICYCLONE CENTER AT 13N138W COVER LARGE PORTION OF E PAC MAINTAINING DRY STABLE AIR MASS N OF 13N W OF 115W. TROPICAL MOISTURE ADVECTS NE ON WRN PERIPHERY OF RIDGE N OF 18N W OF 134W. SECOND ANTICYCLONE ALOFT AT 15N101W PROVIDES LOW SHEAR ENVIRONMENT AND GOOD OUTFLOW OVER SURFACE LOW PRES CENTER AT 14N103W. WITH PLENTY OF HEAT ENERGY AVAILABLE AS SEA SURFACE TEMPERATURES REMAIN ABOVE 28 DEG CELSIUS...LOW PRES IS EXPECTED TO INTENSIFY INTO TROPICAL CYCLONE IN 24-36 HRS. ...ELSEWHERE IN THE LOWER LEVELS... WEAKENING LOW PRES 1015 MB AT 21N136W...REMNANTS OF LANE...AND TROUGH FROM 24N136W TO 19N137W DRIFT W WITH FRESH NE WINDS W OF AXIS. TROUGH EXPECTED OUT OF BASIN IN 24-30 HRS. SECOND SURFACE TROUGH FROM 19N111W TO 14N112W DRIFTS W INTO DRIER REGION MENTIONED ABOVE WITH LITTLE CHANCE OF INTENSIFICATION FRESH N WINDS FORCED ACROSS CHIVELAS PASS IN MEXICO EMERGE AS STRONG N TO NE WINDS IN GULF OF TEHUANTEPEC. WINDS EXPECTED TO INCLUDE GUSTS TO NEAR GALE FORCE THROUGH FORECAST PERIOD. $$ WALLY BARNES